<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  
</head>
<body>
  <div id="app">
      <button @click="createMsg">创建一个数据</button>
      <div v-if="isShow">
        <button @click="changeMsg">修改这个数据</button>
        {{ msg }}
      </div>
  </div>
  <script src="./vue.js"></script>
  <script>
    const vm = new Vue({
      el: '#app',
      data: {
        isShow: false
      },
      methods: {
        createMsg(){
          this.msg = '你好vue';
          this.isShow = true;
        },
        changeMsg(){
          this.msg = '数据修改了';
          console.log(this.msg);
        }
      }
    })
  </script>
</body>
</html>